The present invention relates generally to a stabilization system for a device having a self-propelled chassis. More particularly, the invention relates to a stabilization system for a mobile medical diagnostic device which requires stabilization of the device during analysis of a patient.
Various types of equipment are made mobile by mounting the equipment on a self-propelled chassis. Mobility is particularly significant for medical diagnostic equipment, such as an X-ray device and a scintillation camera device for obtaining diagnostic images of a patient. In many cases, the patient requires intensive care or critical care and cannot be moved, so the diagonostic device must be transported to the patient. The device may be required to be operated virtually anywhere in the hospital. The device must maneuver along extremely long corridors, around life support systems and around monitoring systems or traction devices. The device must also move in and out of elevators, through doorways, up wheelchair ramps, over carpeting and tile, and across small open thresholds.
A problem is presented by the mobilization of scintillation camera equipment equipment which is used to detect gamma ray photons emitted from a body in which a radioisotope has been infused to produce a diagnostic image of the patient. Scintillations occur where photons are absorbed by crystalline material. The scintillations are received by a detector head which contains scintillation crystals, photomultiplier tubes and lead shielding. A typical system is based on the camera of Anger, as disclosed in U.S. Pat. No. 3,011,057, and is herein incorporated by reference. The detector head, along with the suspension arm, weighs approximately 300 pounds. The suspension system and column for the detector head add more weight along with the very high density of electronic instrumentation used to analyze and display the diagnostic images of the patient. The substantial size and weight of the diagnostic equipment requires a similarly substantial chassis and mobility drive system to transport the equipment. The combined equipment and mobility chassis weighs over 2,000 pounds and presents the problem of safely maneuvering, steering and braking the device while it is being moved and then stabilizing the device once it is in position.
Typical mobility chassis of the prior art use conventional four-wheeled system which provides a good stable base when the device is stationary in a desired location. However, the four-wheeled system has a relatively large turning radius and is not as maneuverable as would be desired. A three-wheeled system, having a central steerable wheel has a relatively tight turning radius and is extremely maneuverable. A particular problem with the mobile maneuverable three-wheeled system is presented once the device is relocated and positioned for analysis of the patient. The heavy detector is extended to the side of the device and the three-wheeled system does not provide a sufficiently stable base for the device.
Accordingly, one object of the present invention is to provide a mobile medical diagnostic device which is extremely compact and which is maneuverable within a hospital.
Another object is to provide a diagnostic device which is extremely maneuverable while mobile and which is extremely stable while positioned for analysis of a patient.